1. Googler wants a promo. They know they need to "launch" to get promo. They can't get a promo if they just improve or maintain something that already exists.
2. Googler gets together with other googlers and puts together something they could launch. Nobody cares if it makes any sense.
3. The thing launches. Googler gets their promo. It is now pointless to spend any effort on maintaining something that you can't "launch" again. Googler moves on.
4. Project dies and gets shut down after a while because no sane person would touch maintenance work with a 10 foot pole.
9 out of 10 projects at Google go through this lifecycle, pretty much verbatim. This is why you have three different Google-provided messsengers on Android, and why stuff launches with great fanfare and then quickly runs out of steam. You get the behavior you reward. This is what Google rewards.